The Osteoarthritis Initiative (OAI) is a multi-center, longitudinal, prospective observational study of knee osteoarthritis (OA). The overall aim of the OAI is to develop a public domain research resource to facilitate the scientific evaluation of biomarkers for osteoarthritis as potential surrogate endpoints for disease onset and progression.

The 2008-launched German Family Panel pairfam (“Panel Analysis of Intimate Relationships and Family Dynamics”) is a multi-disciplinary, longitudinal study for researching partnership and family dynamics in Germany. The annually collected survey data from a nationwide random sample of more than 12,000 persons of the three birth cohorts 1971-73, 1981-83, 1991-93 and their partners, parents and children offers unique opportunities for the analysis of partner and generational relationships as they develop over the course of multiple life phases.

The United States Census Bureau (officially the Bureau of the Census, as defined in Title 13 U.S.C. § 11) is the government agency that is responsible for the United States Census. It also gathers other national demographic and economic data. As a part of the United States Department of Commerce, the Census Bureau serves as a leading source of data about America's people and economy. The most visible role of the Census Bureau is to perform the official decennial (every 10 years) count of people living in the U.S. The most important result is the reallocation of the number of seats each state is allowed in the House of Representatives, but the results also affect a range of government programs received by each state. The agency director is a political appointee selected by the President of the United States.

The German General Social Survey (ALLBUS) collects up-to-date data on attitudes, behavior, and social structure in Germany. Every two years since 1980 a representative cross section of the population is surveyed using both constant and variable questions. The ALLBUS data become available to interested parties for research and teaching as soon as they are processed and documented.